Computational simulation and fabrication of smooth edged passive micromixers with alternately varying diameter for efficient mixing

To improve the efficiency of passive micromixers, microchannels of varying geometry have been widely studied. A highly efficient passive micromixer was developed by alternatively varying the cross-sectional diameter along the flow. Microfluidic channels of various geometries were designed and the fluid flow patterns were studied using COMSOL Multiphysics. The extent of mixing in the microchannels for the various designs were analyzed and the most efficient micromixer was further optimized for best mixing performance. The optimized design was fabricated using direct laser write lithography. The spin speed, exposure energy, baking temperature, baking and development time were observed to play an important role in fabrication. Experimental evaluation of the simulation results was carried out by injecting coloured solutions through the PDMS microchannels and by electrochemical studies. Display Omitted Numerical studies using Comsol Multiphysics to optimize the geometry of a passive micromixer.Meander channels with alternately varying diameter were effective in mixing at a shorter length.Fabrication of the optimized microfluidic design using direct laser write lithographyVerification of simulation results by flow visualization experiments